1. Field of the Invention
The present invention relates to an information providing system comprising an information server for providing information upon receipt of request of the information, and a retrieval engine for retrieving an information server capable of providing information requested, and a mediating apparatus for constructing the information providing system.
2. Description of the Related Art
Hitherto, there is known an information providing system having, as an information source, information servers and homepages, distributed on a network such as the Internet, for providing information by the information source. It often happens that such an information providing system is provided with a retrieval engine for retrieving a desired piece of information so that a user of the system can easily to find the desired piece of information.
The retrieval engine stores an index representative of an information group capable of providing information servers and homepages so that information is effectively retrieved, and retrieves information using the index.
Generally, information provided from the information servers and the like constituting the information providing system is often renewed. And thus, there is a need to renew the index to retrieve the up-to-date information by the retrieval engine. As a scheme of renewing the index, hitherto, there are known a plurality of schemes as will be described hereinafter.
First, there is known a so-called PULL scheme.
FIG. 1 is an illustration showing an information providing system for performing a renewal of the index in accordance with the PULL scheme.
FIG. 1 shows an information providing system 1 comprising three information servers 2 and two retrieval engines 3. A user 4 of the information providing system 1 accesses the information servers 2 and the retrieval engines 3 via the Web browser 4a to receive an introduction of the information server and the provision of information.
According to the information providing system 1 shown in FIG. 1, the retrieval engine 3 suitably accesses the information servers 2, so that the index stored in oneself is compared with an information group capable of being provided by the information servers 2 to check accuracy of the index. In the event that the index is inaccurate, the retrieval engine 3 collects from the information servers 2 a renewal information in which the information group capable of being provided by the information servers 2 is represented in the form of a difference from the current index, and renews the index stored in oneself in accordance with the renewal information. This is a renewal of the index according to the PULL scheme.
To always maintain accuracy of the index, it is necessary to promptly collect renewal information whenever information capable of being provided by the information servers 2 is renewed. However, in a network such as the Internet, there exists a large number of information servers 2, and it often happens that the information servers 2 are added or deleted per se. Thus, according to the PULL scheme, it is very difficult to always grasp a present situation of the information servers 2 at the end of the retrieval engine 3. Further, to always maintain accuracy of the index, it would impose a great burden on a manager and a system of the retrieval engine 3.
As a scheme of solving disadvantages of the PULL scheme, there is shown a so-called PUSH scheme.
FIG. 2 is an illustration showing an information providing system for performing a renewal of the index in accordance with the PUSH scheme.
In a similar fashion to that of the information providing system 1 shown in FIG. 1, an information providing system 5 shown in FIG. 2 also comprises the information servers 2 and the retrieval engines 3. According to the information providing system 5 shown in FIG. 2, each of the information servers 2 incorporate therein a push program 6 for automatically producing renewal information and sending the same to the retrieval engines 3.
The push program 6 of each of the information servers 2 produces the renewal information and sends the same to the retrieval engines 3 when the information group capable of being provided by the information servers 2 is altered. Sending the renewal information is referred to as “push”. The retrieval engine 3 renews the index of oneself upon receipt of the renewal information pushed by the information servers 2. This is the renewal of the index according to the PUSH scheme. According to the PUSH scheme, the index stored in the retrieval engine 3 is always an exact index, and thus the user 4 can receive a high quality of retrieval service according to the exact index.
By the way, in general, an information providing system incorporates therein a plurality of types of retrieval engines that are mutually different in a retrieval method of information and in a field of information to be retrieved. Each of the plurality of types of retrieval engines stores an index for the associated retrieval engine. For this reason, according to the information providing system 5 shown in FIG. 2, the push program 6 of each of the information servers 2 produces the renewal information and sends the same to the retrieval engines 3. As retrieval service is expanded or altered in an information providing system, it is expected that a retrieval engine is added or altered.
In the event that such supplement and alteration of the retrieval engine occurs, in the information providing system 5 shown in FIG. 2, for the purpose of producing the renewal information for the retrieval engine involved in the supplement and alteration, there is a need for a manager and the like of each of the information servers 2 to newly produce the push program 6 of each of the information servers 2. However, the manager and the like of each of the information servers 2 is not always skilled in the retrieval engine involved in the supplement and alteration, and thus in general a production of the push program 6 is a great burden for the manager and the like of each of the information servers 2.
In view of the foregoing, there is considered a system in which a push program is distributed via a network to be incorporated into information servers.
FIG. 3 is an illustration showing an information providing system in which a push program is distributed via a network.
In a similar fashion to that of the information providing systems 1 and 5 shown in FIGS. 1 and 2, an information providing system 7 shown in FIG. 3 also comprises the information servers 2 and the retrieval engines 3. According to the information providing system 7 shown in FIG. 3, each of the information servers 2 is provided with a platform 8 for receiving a push program 6 from a network to incorporate the same into the associated information server 2.
According to the information providing system 7 shown in FIG. 3, the push program 6 for each of the retrieval engines 3 is distributed from the associated retrieval engine 3 and a management center (not illustrated) via a network to the platform 8 of each of the information servers 2, so that the push program 6 thus distributed is incorporated into the information server 2 through the platform 8. The push program 6 thus incorporated produces, in a similar fashion to that of FIG. 2, the renewal information and sends the same to the associated retrieval engine.
In the event that a retrieval engine is supplemented to the information providing system 7 shown in FIG. 3, the push program for the supplemented retrieval engine is produced by a person skilled in the retrieval engine, for example, a manager of the retrieval engine and an engineer of a management center, and the push program thus produced is distributed via a network to the platforms 8 of the respective information servers 2.
Thus, the information providing system 7 shown in FIG. 3 can cope with the supplement and alteration of the retrieval engine.
By the way, in the future, it is desired to constitute an information providing system provided with a number of retrieval engines, in which retrieval services of the respective retrieval engines are specialized. For example, it is desired to provide a private retrieval engine for the user 4. Thus, in the event that such a number of retrieval engines are provided for the information providing system 7 shown in FIG. 3, it is needed that a number of push programs 6 for each of such a number of retrieval engines are incorporated into all the information servers 2 constituting the information providing system 7 so that a number of pieces of renewal information is pushed in accordance with such a number of push programs 6. This imposes a great burden on the information servers 2.
In the event that such a number of push programs 6 are produced on a batch basis in a management center and the like and then distributed, it would impose a great burden on the management center. In the event that a manager on each retrieval engine produces and distributes the push program 6 for one's own retrieval engine, there is a high possibility that it is difficult to produce and distribute the push program 6 suitable for the respective information servers, for example, since the manager for the private retrieval engine is the user 4 as a private person.